The history of life on earth is a story of continually larger degrees of organization. We have gone from single celled organisms to multi-cellular organisms, from tribes to cities and countries. It has been several hundred years since we have colonized the useful parts of our planet. Even so, we still have the divide of countries and they remain the dominant organizing force. World level organizations have not yet proved useful enough to gain the leverage needed to exert a positive impact on the world however necessary it may be. With the introduction and development of machine learning and artificial intelligence, we may very well be on the verge of being able to produce systems which can provide significant value at a global scale above what soverign governments can provide today.
Currently, world level organizations exist mainly as working groups which coordinate between soverign governments or as mechanisms supporting them. The largest being the United Nations which is still unable to overcome vetos from the permanent members of the UN Security Council. In recent years, corporations have grown to a scale where they have started to be able to exert cross-national influence. They have in turn formed the World Economic Forum which coordinates and encourages cooperation among these members. It still however acts primarily as a guiding force insteading of being able to exert mandates on its members. The notable exception to corporate power is China, where businesses are decisively positioned under the government.